This invention relates to computerized tutoring systems to teach Morse Code, and in particular to a system containing a computer interfacable code practice oscillator capable of inputting an operator's sending of code to a computer, wherein it is analayzed to determine the operator's "amateur accent".
Inventions in the past that have dealt with Morse code tutoring generally fall into two categories: those that produce code automatically, either for the purpose of teaching it or for otherwise handling it; and those that aid in the process of learning it.
Of the former, there are many inventions in the 1960s and earlier that produce code from some input denoting characters to be coded: most of them are mechanical or electromechanical devices of one kind or another; some are designed specifically to teach code and most are not. However since the proliferation of low-cost computers, the development of programs that can produce code from character input is now within the ordinary skill of an experienced programmer, and there exists on the market many programs that produce code, and many devices that interface to computers to handle the outputted code, such as code practice oscillators and ham radio interfaces. There are also interfaces and computer programs that decode received Morse code from an external source, such as a radio receiver, and display the resultant characters.
Of the latter, there are many learning aids, most of them mechanical devices to aid in memorizing the dit-dah pattern of the characters for the first time. These are generally of little use in helping the learner get his receiving speed up to the thirteen words per minute required of the General amateur radio license, to say nothing of the eighteen wpm required of most military schools or the twenty wpm required of the Amateur Extra Class license. However one patent, U.S. Pat. No. 3,373,507, by Judson Cornish, is a system of mnemonics to facilitate high-speed receiving of code.
Although there are today computer programs and interfaces that generate random groups of characters and encode and output them for an operator to receive, and check his results after the operator has inputted them; and also can generate a message similar to the "QSO" type message used in the FCC code exam for the amateur license, output it to the operator in code and check his decoding; there is nothing that generates a lesson that is "slanted" to an operator's demonstrated weak points. And more importantly there is no system that helps an operator overcome his "amateur accent" when he sends code. This "accent" is in effect the lack of consistency in the operator's dit length, dah length and the length of spaces between dit/dahs, between characters and between words, and departure of the proper ratios between these lengths from what they should be for best reception. A good code operator must be able to send code that can be received by another as easily as he is himself expected to receive from another. Since the "accent" is a matter of time intervals, his sending is capable of being analyzed for what those time intervals are. Every dit and every dah in a message, as well as the space between each one, is capable of being measured for duration. These lengths can be classified or grouped; indeed, this is mentally what we do in recognizing dits from dahs; and also the space length is analyzed to distinguish dit/dah separations from character separations and word separations. The computer program can do this too, not only for the purpose of distinguishing but for the purpose of finding averages and deviations from averages. The average dah length is compared to the average dit length, and the standard deviation is determined. The average space length between dits and dahs is likewise determined, and also the average space length between characters and between words. All of this information is reported to the operator, along with the translated code he sent and any unrecognizable characters.
The object of this invention, therefore, is to provide a system for learning Morse code consisting of a program for a micro computer and a code practice oscillator interfacing to it. Firstly, it provides for the operator to send code with a straight key and, in addition to decoding his output, analyzes the output for salient quantitative parameters of his "amateur accent": standard deviation of his dit length and his dah length, ratio of dah length to dit length, ratio of dit/dah spacing to dit length, ratio of character spacing to dit length, and ratio of word spacing to dit length. And secondly, it provides for a stream of characters to be generated, either random groups or a QSO-type message, encoded and played to the operator, and when the operator responds with the decoded message input to the computer, compares that input with the message originally generated and, noting errors in the operator's response, generates a second stream of characters that is enriched in those characters to which the operator responded incorrectly.